Green Lake in Upper Styria, Austria

Grüner See (Green Lake)
is a lake in Styria, Austria near the town of Tragöß. The lake is surrounded by
the Hochschwab mountains and forests. The name "Green Lake" originated
because of its emerald-green water. The clean and clear water comes from the
snowmelt from the karst mountains and has a temperature of 6–7 °C (43–45
°F). During the winter, the lake is only 1–2 m deep and the surrounding area
is used as a county park. However, during the spring, when the temperature
rises and the snow melts, the basin of land below the mountains fills with
water. The lake reaches its maximum depth of around 12 m from mid-May to
June and is claimed to look the most beautiful at this time. In July, the
water begins to recede.